Background: Single-surgeon series investigating the learning curve involved in surgery for spinal deformity may be confounded by changes in technology and techniques. Our objective with this multicenter, prospective study was to present a cross-sectional analysis of the impact of surgeon experience on surgery for adolescent idiopathic scoliosis. Methods: All posterior-only surgical procedures for adolescent idiopathic scoliosis performed in the 2007 to 2008 academic year, with a minimum of two years of patient follow-up, were included. Two groups were created on the basis of surgeon experience: a young surgeons' group, which included patients of surgeons with less than five years of experience, and an experienced surgeons' group, which included patients of surgeons with five or more years of experience. Results: Nine surgeons (four young and five experienced) operated on a total of one hundred and sixty-five patients with adolescent idiopathic scoliosis. The surgeons' experience ranged from less than one year to thirty-six years in practice. The two groups had similar preoperative curve-magnitude measurements, SRS-22 (Scoliosis Research Society-22) scores, and distribution by Lenke curve type. There were significant operative and postoperative differences. The young surgeons fused an average of 1.2 levels more than the experienced surgeons (p = 0.045). The mean intraoperative estimated blood loss (EBL) of the young surgeons' group was more than twice that of the experienced surgeons' group (2042 mL compared with 1013 mL; p < 0.001). The duration of surgery was 458 minutes for the young surgeons compared with 265 minutes for the experienced surgeons (p < 0.001). The overall SRS-22 scores were significantly worse in the young surgeons' group (a mean of 4.1 compared with 4.5; p = 0.001). The difference between groups was also significant for the domains of pain (p = 0.016), self-image (p = 0.008), and function (p < 0.001). Complication rates did not differ significantly between the groups. Conclusions: Operative results and health-related quality of life following surgery for adolescent idiopathic scoliosis were significantly and positively correlated with surgeon experience. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.